Association of MYC amplification and high-level copy number gains with MYC mRNA expression. The violin plots show MYC mRNA expression levels for tumors within each category. Tumors with MYC high-level gains are separated into subgroups with either 5 to 7 copies or >7 copies. Amplification (Amp) refers to tumors with uncountable copies of MYC. All comparisons were made in reference to the normal group. MYC^Tr is shown for reference. Error bars show the mean and 95% confidence intervals.